Functional disability is common in older adults. It is often episodic and is associated with a high risk of subsequent health decline. The severity of disability is determined by physical impairments caused by underlying medical conditions, and by external factors such as social support, financial support, and the environment. When multiple health conditions are present, they often result in greater disability than expected because the patient's ability to compensate for one problem may be affected by comorbid conditions. Evaluation of functional disability is most effective when the physician determines the course of the disability, associated symptoms, effects on specific activities, and coping mechanisms the patient uses to compensate for the functional problem. Underlying health conditions, impairments, and contextual factors (e.g., finances, social support) should be identified using validated screening tools. Interventions should focus on increasing the patient's capacity to cope with task demands and reducing the demands of the task itself. Interventions for functional decline in older adults are almost always multifactorial because they must address multiple conditions, impairments, and contextual factors.

Professor B. is an 86-year-old woman who presents for a comprehensive geriatric evaluation, stating: “I don't care whether or not you make me live longer, but can you help me live better?” She was a college professor who spent early retirement traveling, earning a pilot's license, and maintaining an active lifestyle. She describes a two-year “downward spiral” that began when she lost her vision rapidly as a result of neovascular macular degeneration. She emphasizes that vision loss is not the only problem: “It just seemed like everything fell apart at the same time.” She has had vertebral fractures, frequent falls, lumbago, osteoarthritis, hypertension, urinary incontinence, mild cognitive impairment, insomnia, depression and anxiety, and idiopathic peripheral neuropathy.

Professor B. is unable to drive or read print smaller than newspaper headlines. She no longer cooks, and requires assistance with finances, medication management, and housekeeping. She has difficulty participating in many previously pleasurable activities, such as entertaining, dancing, and working crossword puzzles. She remains independent in eating, toileting, and ambulating, but she requires assistance with bathing and dressing.

Disability, which is defined as limitation in the ability to carry out basic functional activities, affects one in seven Americans. It negatively affects quality of life and contributes to unsustainable health care costs.1 Although disability may arise acutely from a catastrophic illness, physicians often encounter older adults who present with subacute functional decline without a clear precipitating event.2–4 This article provides a framework for the assessment and treatment of progressive disability in older adults.

Unlike the relatively permanent disability that is often associated with catastrophic injury, disability that results from the accumulation of chronic diseases is dynamic and episodic.4,5 Observational studies have found that most disability episodes are brief (one to two months), but that they increase the risk of recurrent or progressive functional decline.3 The World Health Organization's International Classification of Functioning, Disability, and Health (ICF) model suggests that physicians focus on the physical impairments that result from health conditions, and on factors that affect the patient's ability to adapt to such impairments (e.g., environment, socioeconomic resources).6,7

Common health conditions that may contribute to functional disability include cardiopulmonary diseases, neurologic conditions, diabetes mellitus, cancer, obesity, dementia, affective disorders, ophthalmologic and auditory disorders, and fractures. Some conditions are rare but highly disabling (e.g., stroke), whereas others are less disabling but common (e.g., arthritis).8 The disabling effects vary depending on the task the patient is trying to perform; for example, heart disease is more likely to cause difficulty with tasks that demand high aerobic work (e.g., housework), whereas stroke is more likely to cause difficulty with basic self-care tasks that require limb mobility.9 Impairment refers to a change in body structure or function, often resulting from these chronic health conditions, and may include cognitive impairment, mood disorders, sensory impairment, pain, adverse effects of medications, and gait disorders.7 Both the impairment and the underlying health condition should be addressed to reduce the disability.

The coexistence of two or more health conditions often creates more disability than would be expected. As the number of impairments increases from one to four, the percentage of persons reporting functional dependence increases exponentially (7% to 14% to 28% to 60%).10 Such interactions between impairments may occur because of interference with normal physiologic compensatory strategies. For example, a condition that decreases the biomechanical efficiency of muscles and joints (e.g., arthritis, stroke) increases the work of walking, and a patient with concomitant cardiovascular disease may lack the capacity to compensate for this increased demand.11,12 Interactions may also result from an inability to adopt compensatory behaviors; for example, persons with memory problems have difficulty learning new self-care techniques to compensate for poor eyesight.13 Some combinations of conditions have predominant effects on self-care (e.g., arthritis and stroke), whereas others primarily affect mobility (e.g., arthritis and heart disease).14

According to the ICF model, successful treatment of disability should take into account the patient's personality, compensatory skills, and interaction with the environment.7 These contextual factors have especially important roles in the early and late stages of disability development. Mood, self-efficacy, and personal coping strategies affect self-management of disease, adherence to exercise programs, and long-term health outcomes in patients with diabetes.15 After disability related to end-organ damage occurs (e.g., retinopathy, neuropathy), the physical environment, financial resources to pay for adaptive equipment or assistance, and availability of caregiver support determine whether the patient remains in his or her home or requires a higher level of care.

Because of the complex interactions between health conditions, impairments, and contextual factors, a systematic evaluation and intervention plan is important. Figure 1 depicts a stepwise approach to guide physicians. Evaluation of new or progressive disability begins with characterizing the disability itself and focusing on the course of functional decline, associated symptoms, and specific tasks that have been affected by the disability, including basic activities of daily living.16 Asking the patient about compensatory strategies will inform the treatment plan and provide insight into his or her capacity to cope with functional changes.

Evaluation of New Disability in an Older Adult

Figure 1.

Algorithm for evaluating new disability decline in an older adult.

Evaluation of New Disability in an Older Adult

Figure 1.

Algorithm for evaluating new disability decline in an older adult.

The next step is to identify the underlying health conditions, focusing on those that are potentially modifiable.16 Because many pathologic processes can ultimately cause disability, using an organ system approach is generally the most efficient diagnostic strategy. The focus of the physical examination may be determined by the presenting symptoms; for example, the evaluation of a patient with decreased exercise tolerance and exertional dyspnea would include a thorough cardiovascular and pulmonary examination.

In addition to assessment for underlying health conditions, the examination should include screening for comorbid impairments. Cognitive impairment, mood disorders, pain, poor nutrition, adverse medication reactions, and sensory impairments are modifiable factors that may contribute to the underlying disability and affect the choice of therapy. Determining which condition precipitated the decline is not as useful as understanding the interactions between various health conditions, and targeting treatments to address them. Table 1 lists useful physical examination maneuvers and screening tests to help identify common underlying health conditions and impairments.17–34

Time and Change Test28 (tell the time from a clock face set at 11:10, then make $1 in change from three quarters, seven dimes, and seven nickels; incorrect response on either task suggests possible dementia)

Cognition

Instrumental activities of daily living

Consider cholinesterase inhibitor; driving and home safety evaluation; family education and support

Clock Drawing Test29 (draw a clock face with hands at 11:10; errors in number or hand placement suggest need for further evaluation)

Time and Change Test28 (tell the time from a clock face set at 11:10, then make $1 in change from three quarters, seven dimes, and seven nickels; incorrect response on either task suggests possible dementia)

Cognition

Instrumental activities of daily living

Consider cholinesterase inhibitor; driving and home safety evaluation; family education and support

Clock Drawing Test29 (draw a clock face with hands at 11:10; errors in number or hand placement suggest need for further evaluation)

Finally, the physician should assess contextual factors, including social support, financial resources, and environmental factors. It is important to examine these factors from both the patient's and caregiver's perspectives, because high caregiver burden is common and negatively affects the health of both.35

Effective treatment of disability in older adults is typically multimodal because of the need to address multiple contributing health conditions and impairments, and the importance of simultaneously taking actions to enhance capacity and reduce task demands.16 This complex, multimodal treatment requires a multidisciplinary approach. Referrals to a physical therapist, occupational therapist, nurse, social worker, pharmacist, or nutritionist may be appropriate. Several guidelines provide information on rehabilitation for specific diseases, and provide algorithms to identify the patient population most likely to benefit from rehabilitation.37–39 Close coordination of the timing and types of interventions is required to optimize rehabilitation outcomes. For example, treating delirium and pain before initiating physical therapy will improve patient participation and subsequent outcomes after a fracture.40 Patients with functional decline who do not respond to initial interventions often benefit from comprehensive geriatric assessment, which has been shown to improve function and quality of life, and decrease caregiver burden.41,42

The primary health conditions and impairments underlying Professor B.'s functional decline were vision loss from macular degeneration and mobility-limiting pain in her knees and back resulting from osteoarthritis and vertebral fractures. Comorbid impairments included mild cognitive impairment, depression and anxiety, and adverse effects from psychoactive medications. Supportive contextual factors included adequate economic and social support, a resilient personality, and high baseline function. Environmental challenges included stairs in the home and a rural location that necessitated driving for community involvement.

The following interventions occurred: referral for low-vision rehabilitation and to local services for the blind; referral to a physical therapist to address strength, endurance, and pain; treatment of depression and anxiety with a selective serotonin reuptake inhibitor; and consolidation of the patient's pain and sleep regimens with recommendations for behavioral strategies to reduce anxiety and insomnia, and to decrease the use of psychoactive medications.

Six months later, Professor B. was able to use the stove safely, dress independently, and use magnification devices to read and write. She was listening to recorded books and using a local transportation service for the blind. A physical therapy program improved lower extremity strength and knee range of motion, resulting in reconditioning and significantly fewer falls. Her pain was addressed by a consistent regimen of acetaminophen, heat, and massage. Her depression responded to medication, and her cognition improved with discontinuation of narcotics and reduced use of anxiolytics.

Data Sources: Medline, the Cochrane Database of Systematic Reviews, ACP Journal Club, and the National Guideline Clearinghouse were searched using the following MeSH headings and key words, limited to aged or frail elderly: rehabilitation, activities of daily living, geriatric assessment, functional status, functional decline, and disability. Last search date: April 14, 2011.

The Authors

CATHLEEN S. COLÓN-EMERIC, MD, MHS, is associate director at the Geriatric Research, Education and Clinical Center at the Durham (N.C.) Veterans Affairs (VA) Medical Center, and an associate professor of medicine at Duke University Health System in Durham....

HEATHER E. WHITSON, MD, MHS, is a senior fellow in the Center for the Study of Aging and Human Development, an assistant professor of medicine at Duke University Health System, and a physician in the Geriatric Research, Education and Clinical Center at the Durham VA Medical Center.

Dr. Whitson is supported by NIA K23-AG-032867, the Durham VA Medical Center Geriatric Research, Education and Clinical Center, NIA P30-AG-028716, the Brookdale Foundation, the John A. Hartford Foundation, and the American Federation for Aging Research. Dr. Hoenig is supported by the Mobility RERC, which is funded by the National Institute on Disability and Rehabilitation Research of the U.S. Department of Education under grant no. H133E080003. The opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the U.S. Department of Education.